691020241 has 2 divisors, whose sum is σ = 691020242. Its totient is φ = 691020240.

The previous prime is 691020229. The next prime is 691020259. The reversal of 691020241 is 142020196.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 677300625 + 13719616 = 26025^2 + 3704^2 .

It is a cyclic number.

It is not a de Polignac number, because 691020241 - 2²¹ = 688923089 is a prime.

It is not a weakly prime, because it can be changed into another prime (691020221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345510120 + 345510121.

It is an arithmetic number, because the mean of its divisors is an integer number (345510121).

Almost surely, 2^691020241 is an apocalyptic number.

It is an amenable number.

691020241 is a deficient number, since it is larger than the sum of its proper divisors (1).

691020241 is an equidigital number, since it uses as much as digits as its factorization.

691020241 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 691020241 is about 26287.2638553350. The cubic root of 691020241 is about 884.0909051326.

The spelling of 691020241 in words is "six hundred ninety-one million, twenty thousand, two hundred forty-one".